Air bearing sliders have been extensively used in disc drives to appropriately position a transducing head above a rotating disc. During operation the disc rotates at high speeds, which produces air movement and generates a lift force directing the slider away from the disc and against a load beam causing the slider to fly at an ultra-low height above the disc. The gap between the slider and the disc forms an air bearing. For the transducing head to read and write accurately, a specified head-to-media spacing (HMS), or air bearing gap, must be maintained between the transducing head pole tip and the disc.
As disc storage systems are designed for greater and greater storage capacities, the density of concentric data tracks on a disc is increasing (that is, the size of data tracks and radial spacing between data tracks is decreasing). The higher data storage (or recording) density requires the HMS between each transducing head and the rotating disc be reduced. As the desired HMS decreases, the amount of allowable HMS modulation decreases as well.
The non-flat surface topography of the disc can cause a disturbance or vibration of the air bearing gap of the slider. This disturbance can cause the air bearing gap of the slider to modulate, thereby resulting in HMS modulation. When the air bearing gap modulates, the transducing head cannot accurately read or write to and from the disc.
Maintaining the HMS substantially constant between the transducing head and the disc permits the transducing head to read and write data accurately. Heaters have been used in sliders to adjust the position of transducers through thermal expansion of heated components. Other approaches use microactuators to control the position of the slider.
There is a need for a slider that is capable of maintaining the HMS substantially constant and minimizing the HMS modulation, and is less complex than other active fly height control and high frequency tracking concepts. In addition, for direct contact during recording, it would be desirable to reduce the mass of the recording head that is in contact with the storage media, which would reduce wear of the media.